X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=4b6b497a5b49b504031519b5fcb8137d6a76d1b9;hb=f436bf77ad2eb42228747d9aa58eeb7403e23d49;hp=be0f3451635611df64cfde1517ba2475099026af;hpb=232bf19be43117cdecea054c9a825735f0b47842;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index be0f3451..4b6b497a 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -789,7 +789,7 @@ namespace {
         &&  depth < 8
         &&  eval - futility_margin(depth, improving) - (ss-1)->statScore / 303 >= beta
         &&  eval >= beta
-        &&  eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins.
+        &&  eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins
         return eval;
 
     // Step 9. Null move search with verification search (~22 Elo)
@@ -1163,7 +1163,12 @@ moves_loop: // When in check, search starts here
           if (singularQuietLMR)
               r--;
 
-          // Increase reduction if next ply has a lot of fail high else reset count to 0
+          // Dicrease reduction if we move a threatened piece (~1 Elo)
+          if (   depth > 9
+              && (mp.threatenedPieces & from_sq(move)))
+              r--;
+
+          // Increase reduction if next ply has a lot of fail high
           if ((ss+1)->cutoffCnt > 3 && !PvNode)
               r++;